The Scent Of A Flower
(Inside Science) -- Would a fresh bouquet of flowers lose its appeal if it didn’t smell? Or what if you could no longer buy your favorite perfume? Find out why scientists are studying how pollution is interfering with flowers’ scents.
“I’ve always loved plants. I love flowers in particular; I love smelling them. I’m also really interested in chemistry. I actually majored in chemistry as an undergrad, and also perfumery. The research that I do, it’s a perfect mix of all these topics of interest for me. I’m investigating in particular is how pollution affects the ability of floral scent to be transmitted through air,” said Jeremy Chan at the University of Washington.
And being able to actually “smell the roses” is a big part of any flower’s allure. But how does pollution affect a flower’s scent?
“Let’s say you were standing a few hundred meters downwind of the flowers. Are you able to smell the flower? And it turns out that where the chemical compounds that are in the atmosphere affect the ability of floral scent to travel distances,” said Chan.
And if pollinators like bees, butterflies and moths can’t pick up a flower’s scent, then these insects can’t do their job. To help them, first, scientists need to measure how far a flower’s scent can travel.
“It is really hard because, you might imagine, these scent compounds are present in the atmosphere at tiny concentrations; the atmosphere is mostly air, and even so, you don’t feel much when you move your hand through the atmosphere. The best machines that we have can really detect these floral scents maybe a few meters away from the flower, but we know from observations that pollinators can detect floral scents from up to a kilometer away,” said Chan.
One example that Chan studies is the hummingbird moth.
“I measured the electrical responses of the insect antennae to floral scent, which is a measure of what they’re detecting. And I found that the responses were actually much higher to the oxidized gases than to the floral scent itself. That was kind of confusing,” said Chan.
Unfortunately, the moth was “smelling” all the scents in the air including the flowers and pollution.
“For the pollinators, it represents a lot of noise. It’s like trying to listen to a conversation with another person, in a room full of other people that are yelling at each other,” said Chan.
The next step for Chan and his colleagues is to measure how far floral scents can travel when the concentration of gases, like ozone, change inside a large, closed room.
“Then we can release pollinators, in this case the large hummingbird moth, to observe the scent-tracking behavior in the room, and how it’s impacted when we change the levels of these atmospheric gases,” concluded Chan.
Chan hopes to study pollution and pollinators to keep floral fragrances in the air, flower bouquets and your perfume bottle.
